Magnetic Field Assisted Quench Propagation as a New Concept for Resistive Current Limiting Devices

We present a superconducting current limiter concept based on Melt Cast Processed (MCP)-BSCCO 2212 bulk material. Key feature is a novel protection technique using the strong magnetic field dependence of critical current density of the BSCCO material. A coil is physically wound around a superconducting tube and electrically connected in parallel. If hot spots develop, a part of the current shunts on the coil and the resulting magnetic field brings the superconductor to a rapid and homogeneous quench. Experimental evidence is shown, that superconducting tubes (normal operating current: 1000 A at 77K) are protected effectively, also in the particularly dangerous small load regime and if several components are connected in series. Electric fields up to 2.5 V/cm were achieved without damaging the samples. As a consequence the required superconducting length and with it the AC-losses under normal operation conditions are strongly reduced compared to the usual resistive shunt concepts.